1. Field of the Invention
The present invention relates to an endoscope conduit switching apparatus for performing conduit switching of air/water feeding fluid conduits in an endoscope.
2. Description of the Related Art
Conventionally, endoscopes that are configured by having insertion portions formed into elongated shapes have been widely used in the medical field, the industrial field and the like. Of the endoscopes, a medical endoscope which is used in the medical field is configured to be capable of observing an organ in a body cavity by an elongated insertion portion being inserted into a body cavity which is a subject, and applying various treatments by using a treatment instrument inserted into a treatment instrument insertion channel which is included in the endoscope in accordance with necessity. An industrial endoscope which is used in the industrial field is configured to be capable of performing observation and inspection of a state of an inside of an object, for example, scratches, and corrosion by an elongated insertion portion being inserted into an inside of an object, for example, a jet engine or a plant piping.
In a conventional endoscope as above, an observation window and an illumination window are provided on a distal end face of the insertion portion, and the conventional endoscope is configured so that the inside of a body cavity which is an object to be observed can be observed via the observation window, and illuminating light can be emitted to the inside of the body cavity which is the object to be observed through the illumination window.
Further, in the conventional endoscopes of the configurations as above, especially in the medical endoscopes, body fluids or the like adhere to outer surfaces of the observation windows and hinder observation during use of the endoscopes. For this reason, some of the conventional endoscopes each have an air/water feeding mechanism for feeding a fluid such as water for cleaning the outer surface of the above described observation window toward the outer surface of the observation window, and thereafter feeding gas such as air for drying a lens surface toward the outer surface of the observation window.
The above described air/water feeding mechanism in the endoscope is configured by an air/water feeding nozzle which is provided in the vicinity of the above described observation window and the like on the distal end face of the endoscope insertion portion, a fluid conduit which is inserted and disposed in the insertion portion and an operation portion of the endoscope and is for connecting the above described air/water feeding nozzle and a predetermined air/water feeding apparatus, an operation member which is provided at the operation portion, a conduit switching apparatus which is provided in the operation portion and performs switching of air feeding and water feeding, and the like.
The above described fluid conduit includes a plurality of tubes such as an air feeding tube and a water feeding tube which are formed of flexible tubes, for example. The above described air feeding tube and the above described water feeding tube have respective one ends connected to the air/water feeding apparatus, and have the other ends connected to the conduit switching apparatus. From the conduit switching apparatus, the air feeding tube and the water feeding tube are extended into the insertion portion, and the air feeding tube and the water feeding tube join each other in the insertion portion via a branch tube to be connected to the air/water feeding nozzle thereafter.
By the configuration as above, a cleaning liquid such as water and pressurized air or the like are configured to be able to be properly injected toward the outer surface of the observation window by performing switching of air feeding and water feeding in the above described conduit switching apparatus.
As endoscope conduit switching apparatuses of this kind, endoscope conduit switching apparatuses of various modes have been conventionally proposed by Japanese Patent No. 3651982 and the like, and have been put into practical use.
The endoscope conduit switching apparatuses disclosed by Japanese Patent No. 3651982 described above and the like each have a cylinder to which a plurality of conduits (an air feeding tube, a water feeding tube and the like) provided in the endoscope are connected, and a piston which is fitted to be capable of advancing and retreating in the cylinder, and has a configuration of switching a communication state of the plurality of conduits by an operator.